Method and means for irradiating blood



Jan. 19, 1943. E. K. KNoTT METHOD AND MEANS, FOR IRRADIATING BLOOD Filed May l, 1939 2 Sheets-Sheet l Invenr:

Jan. 19, 1943. E. K. KNorT 2,308,515

METHOD AND MEANS FOR IRRADIATING BLOOD Patented Jan. 19, 1943 METHOD AND MEANS FOR IRRADIATING BLOOD A Emmet K. Knott, Seattle, Wash. Application May 1, 1939, Serial No. 271,072

2s (c1. 12s-395) My invention relates to physical therapy and has for its object the correction of pathological conditions of men or beasts by providing stimulation of and giving energy to the constituent serum and cell structure of the blood and the tissue aected thereby by irradiating a quantity of said blood with energy of the ultra-violet portion of the radiant energy spectrum. The objects and advantages of my present invention will lbe discussed with reference to United States Patent No. 1,683,877, for Means for treating bloodstream infections, issued to Lester A. Edblom an'd myself, September 11, 1928, in order to distinguish said invention from the prior art.

It has heretofore been known that beneiicial results flowed generally from the destruction of infectious bacteria and from inactivation of toxins. A measure of stimulation sometimes followed blood irradiation provided primarily for destruction of infectious bacteria and inactivation of toxins, but said benecial stimulation has been lmore or less inconsistent andhas occasionally .been accompanied by such deleterious eifects las to render ultra-violet blood irradiation therapy inadvisable in certain cases. By the method and means hereinafter described, said beneficial stimulative results are increased and are achieved with remarkable consistency, the deleterious eiects are wholly avoided, and the range of benecial results is extended.

In carrying out my invention, I remove a quantity of blood from the circulatory system of a patient, pass it thru a chamber in which it is exposed to ultra-violet radiation for a brief, accurately controlled period of time, and return it to said circulatory system. The technique includes several important details which will be discussed hereinafter. The most obvious .eiiect ofthis procedure would seem to be the killing of bacteria and inactivation of toxins in the blood stream, and heretofore destruction of bacteria andinactivation of toxins have been the principal objects of blood irradiation. However, I have found that better results will be obtained in most cases if the blood is exposed for a period of time lessthan that necessary directly to kill bacteria. Furthermore, many pathological conditions not accompanied by bacteria, or not caused by bacteria at all, are thereby corrected, whereas they would not be corrected if an exposure suiiicient to kill bacteria directly were used.

The results of irradiating blood according to my present invention may conveniently be divided Y into three groups, classified accordingx to the speed o1 the reaction. First, within a few min.

utes there is noticeable a pink glow of the skin of the face of those patients who are at all pallid,

and the time required for the temporary pallor resulting from pinching the skin to disappear is usually reduced in those patients where this reaction has become sluggish. This appears to be an entirely newphenomenon; it is not produced by the methods of irradiation heretofore lmown, wherein the blood was overexposed. Its significance, insofar as I ampresently aware, is merely that it is a favorable sign; its presence seemingly indicates that other results of the irradiation are to follow in due time, and meanwhile the treatment of lthe patient may be planned accordingly.

However, this pinking, which results from a relaxation of the peripheral circulatory system, probably indicates that there is' an immediate response by the central nervous system to irradiation of the blood, and said response may have further significance not yet fully understood.

' concurrently with the aforesaidpinking, those patients who arerational ordinarily experience an increased feeling of well-being immediately foliowingirradiation according to my invention `that does not occur with the over-irradiation heretofore practiced. The signiiicance of this phenomenon is far greater than is indicated bythe mere comfort of a patient who is only mildly ill, and it should not be confused with the psychological eiect commonly produced by minor surgical operations on naturally optimistic patients. Said stimulative eifect permits treatment of critically ill patients.

In the treatment of disease, in general, promptness 'is anl important factor; many remedies and treatments are eiective only in the early stages of a disease. But early diagnosis and treatment are, unfortunately, not always possible. My invention is adapted to the treatment of cases in which a disease has reached an advanced stage. The patient may be so weakened that any depressive treatment would be fatal. As heretofore practiced, blood irradiation has occasionally resulted in shock and a condition of lowered resistance of the patient, evidenced by a tired feeling and drowsiness. The effect has been similar to, but more persistent than, the well known protein reaction that sometimes follows the injection of serum into the blood stream. Such treatment is not suitable for a critically ill patient. On the other hand, .there are few contraindications for increased by said treatment. The immediate sense of well-being following treatment accord- The second group of results of my invention `take effect in a few hours, rather than a few minutes. The most noticeable of these results is the reduction of body temperature in patients having fever. In those diseases which are caused by bacteria, and particularly in cases of bacteremia, in which there are bacteria in the blood stream, it would seem that the older method in which the blood is exposed to ultra-violet radiation for sufficient time to kill directly .the bacteriain the blood stream would be more 'effective than the method of my present invention. However, experience has shown that, with few exceptions, the contrary is true; in most bacterial diseases better results will be achieved by the shorter exposure. In certain cases, the direct lethal action of ultraviolet of the older method may be used advantageously provided the patient has sufficient vitality to withstand any depressive action thereof.

Indicative of the way in which the short exposure method of my present invention is effective in4 bacterial diseases is the fact that the opsonic index of the blood is thereby markedly increased, that is, the rate of destruction of bacteria by certain white blood cells is increased. coincidental with this phenomenon, and probably causative thereof, the oxygen content of the blood is almost invariably increased in those patients in which said oxygen content was below normal. Again, this effect is in strong contrast to that sometimes produced by the older method in which a portion of the blood was over-exposed, in which case the increased oxygen content is not only absent, but a contrary result is produced in that the hemoglobin of the blood is thereby converted into methemoglobin. Hemoglobin' is a chemically active substance having the ability to absorb oxygen, increased'above a certain value as it normally is in the lungs, and of giving up said oxygen when the pressure is lower, as it normally is in other parts of the body. On the other hand. methemoglobin is an inert substance that will not absorb or give up oxygen under varying pressure. Under conditions comparable to those herein described, the change from hemoglobin to methemoglobin has been observed spectroscopically to take place after an exposure of less than one minute, the exact minimum exposure not being known.

Another result of irradiation that occurs consistently when the method of the present invention is used is an increased red cell count in those patients in which this count is below normal, that is, the number of red c ells per cubic millimeter of blood is increased. This effect will usually be noticeable with 24 hours after irradiation, although this immediate effect may be somewhat obscured by the natural periodic variation in said red cell count, and ordinarily will continue to increase for several days. Here-again, the result is in sharp contrast to that produced by the older method; over-irradiation, when p resent, has been observed consistently to result in a decrease in the red cell count beginning usually within 24 hours and continuing for a few days. after which said red cell count might increase if the disease were overcome.

A somewhat less prompt result is the normalizing of the white cell count, which usually requires several days. If the' white cell count is low, it will gradually increase whereas if it is high it will decrease, probably as certain bacteria are overcome.

The third group of results of my invention require several months for their full effect, although it is not necessary that treatments be continued during this period. By way of example, patients having arthritis of long duration and whose joints are badly deformed by calcium deposits have been given a series of 3 irradiations a few days apart. Improvement in subjective symptoms, pain and stiffness, frequently were observed within 2 or 3 weeks. and in about 3 months objective improvement was shown by X- ray photographs. Complete recovery of many of these cases resulted in 4 to 6 months'after treatment. I am aware thatA spontaneous recovery of some cases of arthritis have been reported, so that the effectiveness of a treatment cannot be judged by a few recoveries. A substantial number of patients have been treated by my method and complete recovery has resulted in more than 6'7 per cent of all cases, a result never before attained by any other treatment with which I am familiar. .'Ihe reason for the failures is not apparent; they have not been limited to the more severe cases of long duration.

The aforesaid recovery of arthritic patients is believed to be due to the increased activity of those white blood cells that are adapted to remove and transport solid matter, such as bone,

. from one location within the body to another.

when the pressure thereof is saidfblood toward the source This activity, like the increased phagocytic power of other white cells. may be due directly to the increased oxygen content of the blood.

Apparatus for irradiating blood is describedin said United States Patent No. 1,683,877 for Means for treating blood stream infections, issued to Lester A. Edblom and myself September 11, 1928. The method of my present invention differs, in one respect, from that disclosed in said patent in that I now remove a quantity of blood from a patient, irradiate it, and return it, preferably thru the same -hollow needle thru which it was removed.

A further difference between my present invention and the method described in said patent is in the time of exposure. Said patent teaches that the blood should be exposed for sumcient time to kill bacteria, that exposures of 5 to 10 seconds are insuillcient for this purpose, and that no harmful results will ensue unless exposures of more than a minute are given. I now regard the optimum exposure to be only a fraction of a second, although I realize that infectious bacteria be directly killed, and I conmay not thereby sider exposures of 5 seconds or more to be detrimental and to be used withv caution.

It should be understood that the word exposure, as used herein, means the time that an individual particle of blood is effectively exposed to ultra-violet radiation, and not to the time required for a particle of blood to pass through an exposure chamber. Inasmuch as the ultraviolet radiations penetrate blood only to a relatively slight depth, it is evident that only those particles immediately adjacent that surface of of radiations will be exposed, and that each individual particle will remain in this region of effective exposure only a small fraction of the time required for it to pass thru the chamber. Thus, an exposure of a small fraction of a second-in the exposure chamber ing to control the actual yneedle is cleaned.

hereinafter described will be achieved-if the blood passes thru said chamber in 4 to 5 seconds. I have obtained better results by thus controlling the average exposure of a large number of individual blood particles, rather than by attemptexposure of each individual particle.

The principal object of my invention is to treat pathological conditions of the body by removing a quantity of blood therefrom, irradiating said blood for a period of time suiiiciently long to achieve a maximum of beneficial results, and returning said blood to said body.

A further objectof my invention is to treat pathological conditions of the body by intermittently exposing a portion of the blood thereof to' ultra-violet'radiations. I have found that the time of exposure of each blood particle can be more accurately controlled, and the over-exposure of any particle can more certainly be avoided by giving a quantity of blood a series of short exposures rather than one continuous exposure.

A further object' of my invention is to provide means for controlling exposure of blood as it passes into the circulatory system of a patient. Due to spasmodic contraction oi the muscles of the veins, or the them, the vrate of now of needle into said veins may vary over a wide range; at times said flow is reduced to the extent that a long period of time is required for the blood to flow into the vein. Said hollow needle may become plugged by a blood must be interrupted temporarily until said Heretofore, the ultra-violet generator has been manually removed from the posure at all satisfactorily in this way, and, for another reason, even with the most highly skilled operators, the exposure cannot be timed as accurately as is desirable.

' A further object of my invention is to provide a mechanically operated cleaning device for cleaning the interior wall of the transparent crystal or window of an exposure chamber. I have found that, especially if the process of irradiating blood is prolonged, a lm of blood or blood serum tends to accumulate on said crystal, thereby absorbing part of the radiant energy thaty would otherwise be absorbed by the blood flowing thru said chamber. Said lm elective time of exposure uncertain, and it also probably has a selective eiect, that is, it probably absorbs some of the shorter wave length radiations. In order that a quantity of blood may be uniformly exposed throughout the exposure process, I prefer continuously to clean the interior surface of the crystal of the exposure chamber.

Other objects and advantages of my invention will be described the accompanying drawings, in which:

Fig. 1 is a side elevation of blood exposure apparatusl embodying my invention, one of the side Walls oi the base member thereof'being shown broken away to disclose the parts arranged 4within said base; l

Fig. 2 is an end elevation of saidapparatus. portions of the endl wall of the base member and of one of the gears'v being shown broken away 4to disclose parts posterior thereto;

automatically the time of in which case the flow of makes the actual t hereinafter with reference to -end view of the exposure chamber of said ap- Fig. 5 is a longitudinal sectional view taken substantially on the lline 5-5 of Fig. 4,'

Fig. 6 is a diagrammatic View rangement which I prefer of those parts shown in Fig. 1 thru which the blood flows;

YFig. 7 is a view similar to Fig. 6 showing an alternative arrangementof said parts;

Fig. 8 is a view similar to modication of my invention;

Fig. 9 is a more or less diagrammatic enlarged side view of the shutter and cam for operating the same shown in Fig. 1; and l Fig. 10 is an enlarged sectional taken along the line Ill- I0 in Fig. 8.

Blood irradiating apparatus embodying my indetail view at volts. A shutter 4 is removably attached" to said generator by 'clips 5, larranged on either generator, and.spaced therefrom by be provided,

said shutter laterally as well as to space it from generator and shutter may be 'removed from said base as a unit.

pin when rotated. A pillow block Il I5, thereby proready removal of said chamber.

Said triangular produce the proper turbulence,

apertures help as is explained Fig. 6 showing a t around said more fully in my copending application for United States Patent, Serial No. 191,468, for Ultra-violet exposure device 19, 1938.

A sleeve rotatably mounted on said chamber and provided with a lip 2| is adapted to be held in place by bushing 22 threaded on said chamber and provided with an internal lip 23 for engaging said lip 2l. Said. sleeve should fit snugly on said chamber in order to prevent blood flowing therebetween, and to assurethat blood shall not so flow I prefer to provide grooves 24 in said chamber to contain packing material. A clamping ring 25 threaded on sleeve 2li is adapted to hold crystal 2G firmly across the end of said sleeve, a resilient packing ring 21 preferably being positioned between said crystal and said clamping ring to prevent leakage of blood therethru, and to minimize the danger of breaking said crystal. Said crystal should be made of quartz, or some other material similarly transparent to ultra-violet radiations.

Bushing 22 may be turned to 'draw said crystal rmly against the face of said chamber thereby to prevent leakage of blood between said crystal and partitions 2B. I prefer to accurately grind the face of said chamber, including the edges of said partitions, to a flat plane in order that said crystal may t closely thereon. It is important that as few as possible of the blood cells be squeezed between said crystal, as it rotates, and said stationary partitions. The blood cells are rather easily ruptured by mechanical pressure. and, when the hemoglobin from within the red cells is permitted to flow out into the blood serum, undesirable shock symptoms are produced in the patient. The effect of rupturing red blood cells mechanically seemingly is the saine as that of rupturing them by overexposure to ultraviolet radiation.

To minimize the aforesaid rupturing of blood cells, I prefer to rotate said crystal at a very slow speed, say, for example, one revolution per minute. This will ordinarily be sumcently fast to keep said crystal clean by rubbing or scraping against said partitions, which is the object of said rotation. I prefer that said crystal rotate slowly but continually in order that no large amount of deposit shall be scraped loose suddenly, as might occur if said crystal were rotated intermittently by hand, thereby tending to clog the needle thru which the blood is returned to the patients circulatory system. Rotation of said crystal may be conveniently produced by a friction wheel engaging a groove 29 in sleeve 28. Means for rotating said wheel will be hereinafter described.

In order that blood flowing into the circulatory system of a patient may be exposed for the correct period of time, notwithstanding that the rate of now of said blood may vary, I prefer that said blood shall be forced thru the exposure chamber by a positive displacement pump, so that the rate of flow of said blood will be proportional to the speed of said pump. Means for preventing undue pressure of said blood where it ows into the patient will be hereinafter described. A positive displacement pump 3| adapted for pumping said blood may be removably mounted on base I by cap screws 32. Said pump may be driven by means of gear 33 aixed to pump shaft 34. Said pump should be readily disassembled for cleaning, and it should be so designed that blood cells will not be crushed by its operation, for reasons hereinbefore menfor blood, filed Feb.

. also carries a pinion 'ultra-violet energy in asoasie tioned. A suitable pump for this purpose is described in United States Patent No. 1,845,479. for Blood transfusion apparatus, issued Feb. 16, 1932, to John W. Carpenter.

A motor 35 carries a fan 36 on its shaft 31 for blowing air between generator 3 and chamber I2. I prefer to space said members a short distance apart to allow said air to be blown between them in order that the blood in said chamber shall not be unduly heated, especially when the flow of said blood is temporarily obstructed so that it remains within said chamber for a substantial period of time. Although said generator is preferably of the water cooled type, having tubes 38 for carrying cooling water, and suitable electrical connections 38a, its temperature will ordinarily be higher than that to which blood should be subjected. A further result of said spacing is that no substantial amount of ozone will accumulate between said generator and said chamber. With the means for irradiating blood heretofore used, the chamber have been held closely together, with only a relatively small body of stagnant air between. A substantial amount of the oxygen of said stagnant air was converted to ozone by the ultra-violet radiations, and said ozone absorbs the neighborhood of 2250 to 2750 Angstrom units to a high degree. I have not accurately determined the effect of eliminatin g the aforesaid ozonehbut the best results I have retained have occurred under conditions in which little, if any, ozone was present.

Said motor also carries on its shaft 31 a worm gear 39 adapted to rotatably engage gear B8 aflxed to shaft M which carries cam Hl, hereinbefore mentioned, amxed thereto. Said shaft `6H d2 adapted to engage gear 43. xedly secured to shaft 46. From said shaft 45 two trains of gears are driven. The first, including gear i5 meshing with gear 136 xed to shaft 1 as is gear |33 which means with gear t9 xedly secured to shaft 50, is for the purpose of driving friction wheel 30, hereinbefore described, said friction wheel being secured to said shaft 5d. The other gear train, including gear 5| meshing with gear 52 aflixed to shaft 53 to which is secured gear 54 adapted to mesh with gear 33, hereinbefore described, is for the purpose of operating pump 3|.

Other gear arrangements might be used to drive the aforesaid members, but I prefer that pump 3| and shutter 4 be operated by some positive means in order that said shutter may be caused to expose the blood in chamber |2 for a predetermined time when said pump has-caused a predetermined amount of blood to flow thru said chamber. I have found that pump 3| should usually be operated at a speed of about one revolution per second, whereas it may be desired to trip shutter l twice per second. Thus shafts 53 and lll may be caused to rotate at about the same speed if cam ||l is provided with 2 protuberances, as is shown in Fig. 9. However, the speeds of various parts may vary widely under diiferent conditions, and more or fewer protuberances may be provided on cam I0. I prefer motor 35 to be of some variable speed type, and -it may be supplied with electric power from any suitable source thru control box 54. The speed of said motor may then be varied by turning knob 55 of said control box.

In carrying out the irradiation of blood according to my invention, I prefer to remove from the patient an amount of blood amounting to subgeneratorI and the exposure said container to tube should connect the outlet of said chamber I2; and said chamber to in seconds, shutter 4 might be tripped at intervals of 1/2 second, and it might remain open 1A second each time blood is forced into the vein.

` Said attendant may slow down motor 35, thereby reducing the rate at which pump 3i forces blood thru exposure chamber I2, if he sees said blood rise too high in standpipe 58; he may thus tainer 56, in case said attendant neglects to slow down motor 35 when the iiow of blood into a blood vessel becomes obstructed, the overow will be' said graduated chamber exposure, which is objectionable and should be' prevented insofar as possible.

In order to prevent re-exposure of any blood is dispensed with and a somewhat larger reservoir 6| is provided instead of reservoir 59. However, I deem it important that the blood be returned immediately to the patients circulatory system after it has been irradiated. Accordingly, I do not Wish any more blood to he stored in standpipe 58, or the reservoir at its top, than necessary. I, therefore,

ordinarily overilows from said standpipe.

In the art of blood transfusion, it hasheretofore been determined that adapted to seat therein, and a spring 64 for causing said member to seat. The tension'of said spring may be adjusted by rotating cap 65 threaded on said valve, as is shown in Figs. 8 and 10, thereby adjusting the pressure under which said valve will release.

I interpose said valve X62 in a tube, preferably made of glass, one end of which is connected to the tubing'leading from the exposure chamber to the needle, and the other end of which is connected to the tubing leading from graduated container 56 to pump 3|. Thus, if the pressure However, blood flowing thru said valve will be re-exposed, prevent any substantial quantity from so owing. Said ow may be 35, as hereinbefore prevented by slowing motor described. The use of valve 62 will greatly extherefor.l e

While I have described my invention in connection with autotransfusions of blood, it may be pump 3| that no mood 1. In blood transfusion therapy, the methodV of treating a quantity of removed blood immediately prior to its insertion into a patients circulatory system comprising producing turbulence of said blood to Vcause the particles thereof to move towards and from a surface, exposing said surface to a beam of radiant energy of the ultraviolet portion of the spectrum for a time less than that required directly to kill infectious bacteria' in said blood.

2. In blood transfusion therapy, the method of treating a quantity of removed blood immediately prior to its insertion into a patients circulatory system comprising producing turbulence of said blood to cause the particles thereof to move towards and from a surface, exposing said surface to a beam of radiant energy of the ultraviolet portion of the spectrum intermittently for a total time less than that required directly to kill infectious bacteria in said blood.

3. In blood transfusion therapy, the method of treating a quantity of removed blood immediately prior to its insertion into a patients circulatoryl system comprising producing turbulence of said blood to cause the particles thereof to move towards and from a surface, exposing said surface to a beam of radiant energy of the ultraviolet portion of the spectrum for a time such that said particles remain in said beam adjacent said surface for less than one second.

4. In blood transfusion therapy, the method of treating a quantity of removed blood immediately prior circulatory system comprising producing turbulence of said blood to cause the particles thereof to move towards and from a surface, exposing said surface to a beam of radiant energy of the ultra-violet portion of the spectrum intermittently for a total time such that said particles remain in said beam adjacent said surface for less than one second.

5. In blood transfusion therapy, the method of treating a quantity of removed blood immedately prior to its insertion into a patients circulatory system comprising owing said blood across a surface in a stratum of substantial depth, producing turbulence of said blood to cause the particles thereof to move towards and from said surface, exposing said surface to a beam of radiant energy of the ultra-violet portion of the spectrum for a time such that said particles remain in said beam adjacent said surface for less than one second.

6. In apparatus for irradiating blood and immediately returning it to the circulatory system, which apparatus" comprises a conduit adapted to have a quantity of blood to be irradiated passed therethrough and discharged therefrom, and an exposure chamber communicating therewith, said chamber provided with a window permeable to ultra-violet radiation, the combination therewith of means for producing ow thru said chamber at a constant rate, a by-pass channel communicating with said conduit intermediate said chamber'and the point of discharge from said conduitand means arranged in said by-pa'ss for preserving a predetermined maximum pressure in said conduit at'said point of discharge.

'1. In. apparatus for irradiating blood and immediately returning it to the circulatory system,

to its insertion into a patients 4ultra-violet radiation,

which apparatus comprises a conduit adapted to have a quantity of blood to be irradiated passed therethrough and discharged therefrom, and an exposure chamber communicating therewith, said chamber'provided with a window permeable to ultra-violet radiation, the combination therewith a by-pass channel communicating with said conduit intermediate said chamber and the point of discharge from said conduit, and a stand pipe arranged in said by-pass for preserving a predetermined maximum pressure in said conduit at said point of discharge.

8. In apparatus for irradiating blood and immediately returning it to the circulatory system,

comprises a conduit adapted to have a quantity of blood to be irradiated passed therethrough and discharged therefrom, and an exposure chamber communicating therewith, said chamber provided with a window permeable to ultra-violet radiation, the combination therewith of a oy-pass channel communicating with said conduit intermediate said chamber and the point of discharge from said conduit, and means including a pressure relief valve arranged in said by-pass for preserving a predetermined maximum pressure in said conduit at said point of discharge.

9. In apparatus for irradiating blood and inimediately returning it to the circulatory system, which apparatus comprises a conduit adapted to have a quantity of blood to be irradiated passed therethrough and discharged therefrom, and an exposure chamber communicating therewith, said chamber provided with a window permeable to ultra-violet radiation, the combination therewith of a by-pass channel communicating with said conduit intermediate said chamber and the point of discharge from said conduit, and a stand pipe arranged in said by-pass for preserving a predeterminedrnaximum pressure in said conduit at said point of discharge, said pressure controlling means including a chamber in said stand pipe of substantially greater cross-sectional area than said stand pipe connected thereto for retaining a substantial quantity of blood.

10. In apparatus for irradiating blood and immediately returning it to the circulatory system, which apparatus comprises a conduit adapted to have a quantity of blood to be irradiated passed therethrough and discharged therefrom, and an exposure chamber communicating therewith, said chamber provided with a window permeable to ultra-violet radiation, the combination therewith of a by-pass channel communicating with said conduit intermediate said chamber and the point of discharge from said conduit, and a stand pipe arranged in said by-pass for preserving a predetermined maximum pressure in said conduit at said point'of discharge, said stand pipe having a transparent wall section of substantial length to permit observation of the presence of blood in said stand pipe.

1l. In apparatus for irradiating blood andY immediately returning it to 'the circulatory system, which apparatus comprises ya generator of ultra-violet irradiation, a conduit adapted to have a quantity of blood to be irradiated passed discharged therefrom, and an exposure chamber communicating therewith, said chamber provided with a, window permeable to the combination therewith of means for interrupting periodically the beam directed by said generator through said chamber window.

12. In apparatus for irradiating blood and imwhich apparatus mediately returning it to the circulatory system, which apparatus comprises a generator of ultraviolet irradiation, a conduit adapted to have a quantity of blood to be irradiated passed therethrough and discharged therefrom, and anex- V posure chamber communicating therewith, said chamber provided with a window permeable to ultra-violet radiation, the combination .therewith of a shutter having arelatively :fixed speed of operation for interrupting .periodically the beam. directed by said generator through said chamber window.

13. In apparatus for irradiating blood and immediately returning it to the circulatory system, which apparatus comprises a Agenerator of ultraviolet irradiation, a generator of ultra-violet radiation, a conduit adapted to have a quantity of blood to be irradiated passed therethrough and discharged therefrom, and exposure chamber communicating therewith, said chamber provided with a Window permeable-to ultra-violet radiation, said window adapted to be arranged adjacent and facing said generator and to have ultraviolet radiation directed therethrough, the combination therewith of means periodically the beam directed by`said generator through said chamber window. r

14. In apparatus for irradiating blood and immediately returning it to the circulatory system, which apparatus comprises a generator of ultraviolet irradiation, a conduit adapted to have a quantity of blood to be irradiated passed therethrough and discharged therefrom, and an exposure chamber communicating therewith, said chamber' provided with a window permeable to ultra-violet radiation, the combination therewith of means for interrupting periodically the beam directed by said generator through said chamber window, and means for varying said means to vary the number of actuations of the latter per unit of time.

for interruptingl mediately returning it to the circulatory system, which apparatuscomprises a generator of ultraviolet radiation, a conduit adapted to have a quantity of blood to be irradiated passed therethrough and discharged therefrom, and an 'exposure chamber communicating therewith,'said chamber provided with a window permeable to ultra-violet' radiation, said Window adapted to be arranged adjacent and facing said generator and to have ultra-violet radiation directed therethrough, the combination therewith of means arranged adjacent the window of said exposure chamber adapted to direct a current of air across said window and intermediate the latter and said ultra-violet generator.

18. In apparatus for irradiating blood and immediately returning it to the circulatory system, which apparatus `comprises a generator of ultraviolet radiation, a conduit'adapted to have a quantity of blood to be irradiated passed therethrough and discharged therefrom, and an exposure chamber communicating therewith, said chamber provided with a window permeable to ultra-violet radiation, said window adapted to be arranged adjacent and facing said generator and to have ultra-violet radiation directed therethrough, the combination therewith of means arranged adjacent the Window of said exposure chamber adapted to direct a current of air across said window and intermediate the latter and said ultra-violet generator in such quantities as to maintain said window substantially below body 15. Inapparatus for irradiating blood and immediately returning it to the circulatory system,

which apparatus comprises a conduit adapted to of said body, said window pane extending across .and bearing upon said partitions, the combination therewith of means for cleaning the inner surface of said window pane including means for moving said pane relatively across said partitions.

16. In apparatus for irradiating blood and immediately returning it to the circulatory system, which apparatus comprises a conduit adapted to have a quantity of blood to therethrough and discharged thereirom and an exposure chamber communicating therewith, said chamber provided with a window pane permeable to ultraviolet radiation, said chamber comprising a cup-shaped body having a plurality of transverse partitions extending through the cup of said body, said window pane extending across and bearing upon said partitions, the combination therewith of means for cleaning the inner surface of said window pane including means for moving said pane relatively across said partitions, said means being arranged externally of said chamber.

17. In apparatus for irradiating` blood and imbe irradiated passed v heat and to remove rapidly and prevent the accumulation of ozone generated byl said ultraviolet radiation.

19. In apparatus for irradiating blood and immediately returning it to the circulatory system, which apparatus comprises a generator of ultraviolet radiation, a conduit adapted to have a quantity of blood to be 'irradiated passed therethru and discharged therefrom, and an exposure chamber communicating therewith, said chamber being provided with a window permeable to ultra-violet radiation, the combination therewith of adjustable means for producing a selected rate of ow thru said chamber, and means for interrupting periodically and rapidly the beam directed by said generator thru said chamber window, said latter means being operatively connected with the means for producing iow thm said chamber so as .to correlate the frequencies of interruption of said beam with the rate of ow thru said exposure chamber.

20. In apparatus for irradiating blood and immediately returning it to the circulatory system, which apparatus comprises a generator of ultraviolet radiation, a conduit quantity of blood to be irradiated passed thereand an exposure chamber communicating therewith, said chamber being provided with a window permeable to ultra-violet radiation, the combination therewith of adjustable means for producing a selected rate of flow thru said chamber, means for inadapted to have a imum pressure in said conduit at said point of discharge, said stand pipe having a transparent wall section of substantial length to permit observation of the presence of blood in said stand plpe.

21. In apparatus for irradiating blood and immediately returning it to the circulatory system, which apparatus comprises a conduit adapted to have a quantity of blood to be irradiated passed therethru and discharged therefrom, and an exposure chamber communicating therewith, said chamber being provided with a window permeable to ultra-violet radiation, the combination therewith of a shutter adapted periodically to interrupt a beam of ultra-violet radiation directed through said window, and a power driven cam for actuating said shutter.

22. In apparatus for irradiating blood and immediately returning it to the circulatory system, which apparatus comprises a conduit adapted to have a, quantity of blood to be irradiated passed therethrough and discharged therefrom, and an exposure chamber communicating therewith, said chamber being provided with a window pane permeable to ultra-violet radiation, said chamber comprising a cup-shaped body having a plurality of transverse partitions, said window pane extending across and bearing upon said partitions, the combination therewith of rotary friction means for rotating said pane thereby to clean the inner surface of said pane.

23. In apparatus for irradiating blood and immediately returning it to the circulatory system, which apparatus comprises a conduit adapted to have a quantity of blood to be irradiated passed therethrough and discharged therefrom, and an exposure chamber communicating therewith, said chamber being provided with a window pane per.- meable to ultra-violet radiation, said chamber comprising a cup-shaped body having a plurality of transverse partitions, said window pane extending across and bearing upon said partitions, the combination therewith of rotary friction means for rotating said pane thereby to clean the inner surface of said pane, a shutter adapted to interrupt periodically a beam of ultra-violet radiation directed through said window pane, and a power driven cam for actuating said shutter. 

